It has been a recent trend in Courts of Justice of the industrial world, and more particularly in the United States, to award in medical malpractice cases increasing monetary compensations, which now reach huge amounts. In the United States, for example, several of such monetary compensations are now well in excess of one million dollars per patient; costs of medical liability insurance have accordignly soared, and in certain medical specialties, the yearly premiums almost reach $100,000 (U.S.): this is about five times the Gross National Product per capita of the United States (in 1986); of course, health care fees have increased accordingly, but it is the consumer-patient who ultimately loses on the long run.
Among the doctors in medicine most susceptible of malpractice suits, there are inter alia the anesthesists. One frequent medical act effected by anesthesists is the injection of anesthetic solutions in the blood vessel of a patient. When the patient is to be fully anesthesized, as for a major operation, the anesthesist has to inject the anesthetic solution both before the operation, and during the operation to continuously provide for an adequate level of neuro-muscular release of the patient. This is done with a syringe, and it is always a delicate operation to not only &gt;&gt;find&lt;&lt; the blood vessel with the syringe needle, especially with patients suffering from obesity wherein the blood vessels are embedded in large masses of fat, but also prevent its withdrawal therefrom notwithstanding the inevitable play of the needle in the tissues both during the injection and in between injections when the needle is normally not removed from tissues as during general anesthesy for a major surgical operation.
Of course, physically-damaging consequences to the patient may result from inadequate use of a syringe: for example, abscesses and cutaneous fistules.
There are two main types of syringes: the &gt;&gt;glass&lt;&lt; type and the disposable, single-use type. In the former, often used by anesthesists, means may be provided for regularly verifying if the needle is still in the blood vessel; such means are disclosed in French Pat. No. 7 615 801, issued Feb. 20, 1981 to the present inventor. However, there is a danger that multiple-use type of syringes, such as the glass syringes, may induce once in a while imperfect sterilization of the syringe, and therefore risks of contamination. It is known, for example, that certain strains and viruses can survive for long times on dry substrates and resist against at least some of the sterilization method presently used. In the last few years, the virus of a dangerous and devastatingly-deadly disease has spread over the world, to wit: the AIDS disease. Also, human error and sterilizating machine dysfunction do occur. In view thereof, it is the present inventor's firm belief that the use of non-disposable types of syringe should be completely banned in the future.
Conventional disposable syringes, made of polypropylene, do not have such safety means for regularly automatically verifying if the needle is in the vein. During injection with disposable syringes by health officers, such a safety operation is effected by partially pulling out the syringe piston from the syringe tubular body; if blood backflows into the transparent syringe tubular body, as witnessed de visu by a reddish stream of fluid, then the needle must necessarily be in the blood vessel. This is well known in the art. However, this requires the two hands of the health officer; one for holding the syringe, and one for pulling back the piston centrally with the fluid-ejecting operation, then the health officer may single-handedly support the syringe main body with two or three fingers of one hand and push the piston with the thumb of the same hand.
That two hands are required for verifying that the needle is within a blood vessel is inefficient, time-consuming, and inevitably undesirably induces some play of the needle in the surrounding tissues.
It is also known that piston pull-back in a disposable or one-use syringe requires more effort than in a glass syringe, since the former requires sealing rings around the piston head and these rings produce friction.